I think it's selfish to smoke in front of other people, full stop, unless they also smoke. I used to think it was just annoying, but then I started working in a university health research department and now I can rattle off a list of all the major unpleasant diseases caused by smoking, plus the most accurate current estimate of how likely a smoker is to die as a direct result of smoking. (It is about 50%. Russian roulette, anyone?)

My former boss does a lot of work studying the effects of public health interventions. Time and again he finds that, in any given area (but particularly in poorer areas, where there tend to be more smokers), the most effective and cost-effective thing you can do to increase the general health of the population is to implement smoking cessation programmes that work.